Area Forecast Discussion
Issued by NWS Tucson, AZ
Issued by NWS Tucson, AZ
805 FXUS65 KTWC 222000 AFDTWC Area Forecast Discussion National Weather Service Tucson AZ 100 PM MST Wed Jul 22 2026 .SYNOPSIS... Expect a downturn in thunderstorm activity across Southeast Arizona today with widely scattered showers and thunderstorms mainly east of Tucson today. Although we will maintain a low-grade thunderstorm pattern the next few days, we will also see afternoon high temperatures rapidly increase late this week into this weekend. The upper pattern eventually moves into a more favorable location for an increased potential for strong and organized thunderstorms Saturday and Sunday. && .DISCUSSION... Much of Southeast Arizona is under partly cloudy skies. This is thanks to the lingering moisture in the area. There have been a few cloud build-ups in the mountains, with most of the build-ups in the White and Chiricahua Mountains. As for thunderstorms, the activity has remained to Northern Arizona and East in New Mexico. Can`t rule out a few showers/storms this afternoon and evening, but no where near the intensity and coverage we have seen over the past few days. The downward trend in thunderstorm activity sticks around through Friday as the high pressure reconsolidates. As the threat for storms decreases, temperatures begin to rise. Temperatures will slowly increase into late this week into the weekend, with the hottest days expected on Friday and Saturday. Temperatures will range from 105 to 112 degrees in the Tucson Metro, Western Deserts, and Upper Gila River Valley. Elsewhere temperatures will range from 100 to 105 degrees. This increase in temperatures in combination with the warm low temperatures of 80 to 85 degrees lead to hoisting up an Extreme Heat Warning for Friday and Saturday when temperatures will be 5 to 10 degrees above normal. Major HeatRisk is expected for the valleys, so be aware of the signs for heat illness/stroke, stay hydrated, stay indoors with air conditioning when possible, and consider moving plans indoors during the hottest time of day. The combination of moisture increasing and a favorable upper air pattern will bring back more widespread chances for thunderstorms this weekend. The high pressure sets up in the 4 corners allowing for SE flow and moisture to work into the area. Wind and dust look to be the greatest impacts this weekend, but isolated flash flooding can`t be ruled out. More details will come into focus as we get closer to the weekend. && .AVIATION...Valid through 23/00Z. SCT-BKN 6-8k ft AGL and BKN 12-14k ft AGL with widely scattered showers/thunderstorms generally to the east of KTUS. VFR, with the exception of brief MVFR due to stronger showers and thunderstorms. Surface winds generally less than 12 kts, except for around storms where VRB gusts to 35 kts will be possible. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect a downturn in thunderstorm activity across Southeast Arizona today with widely scattered showers and thunderstorms mainly east of Tucson today. Although we will maintain a low-grade thunderstorm pattern the next few days, we will also see afternoon high temperatures rapidly increase late this week into this weekend. The upper pattern eventually moves into a more favorable location for an increased potential for strong and organized thunderstorms Saturday and Sunday. Min RHs 25-30% in the lower desert locations and above 40% in the mountains today. By Thursday into the weekend, RHs could dip into the 17-22% range for the lower deserts west of Tucson and the upper Gila River Valley as temperatures warm to above average. Winds this week will remain mainly light and under 15 mph, though strong and erratic winds will be possible with any thunderstorm. && .TWC WATCHES/WARNINGS/ADVISORIES... Extreme Heat Warning from 10 AM Friday to 8 PM MST Saturday for AZZ501>509. && $$ JT Visit us on Facebook, X, YouTube, and at weather.gov/Tucson